One of the tasks I’ve been assigned to is updating the process for capturing screen images for training materials. Screen captures are integral to the training materials that IT Training uses in their workshops – they help participants out as they work their way through the workshop, and also help self-study users make sure they’re on track when they work on their own. The previous screen capture methods had been in place for a few years – the last update to the methods was around 2012, when materials were updated to include colored screen shots. Before then, all screen captures were done as black and white TIF files, as the materials were printed and handed out to participants at workshop sessions. As more and more participants were viewing our materials on screen, we had to find a good balance between file size and image quality. The previous screen capture profile (created in SnagIt, a screen capture program that IT Training uses in the materials development process) resulted in 8-bit TIF files, limited to 256 colors, and occasionally resulted in odd transparency issues. As time went on, and printed materials were no longer used in the classroom, it was decided that a new screen capture profile was needed. So, I fired up SnagIt and worked to figure out what the best file format would be for our needs, and what specifications for each format would work best.
I tested out our 8-bit TIF file format in comparison to 24-bit TIF files, as well as 8-bit and 24-bit PNG files. This involved taking lots of screenshots in lots of different programs, and then importing them into FrameMaker to see how they’d look. Below are a few examples of screen captures I took, to illustrate quality differences between the multiple formats I tried.
It turned out that the 24-bit PNG file was the highest quality file and smallest size – the 8-bit versions of both images had some speckling in the images, and the 24-bit TIF file was a little blurry in spots. So, the new file format ended up being 24-bit PNG files.
We also had to take into consideration what resolution we wanted to import the images into FrameMaker at – a larger resolution would result in smaller images, but a larger resolution might end up distorting the images somewhat. The decision to import images at 120 DPI was made after more image testing and comparison – 120 DPI kept the images at a reasonable size without sacrificing quality, and if someone chooses to print the materials, they won’t look terribly pixelated when coming out of a printer.
With those decisions made, and the new SnagIt profile created, my next task is to put the profile to the test and do screen captures for a set of materials.